Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation - Schedule of Share Based Payment Assumptions (Details)

v3.19.3
Stock-based Compensation - Schedule of Share Based Payment Assumptions (Details)
3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Share-based Payment Arrangement [Abstract]        
Volatility, minimum 108.03% 105.85% 108.03% 105.85%
Volatility, maximum 108.06% 109.95% 111.34% 109.95%
Risk-free interest rate, minimum 1.59% 2.84% 1.59% 2.29%
Risk-free interest rate, maximum 1.89% 3.00% 2.65% 3.00%
Dividend yield 0.00% 0.00% 0.00% 0.00%
Expected life 6 years 6 years 6 years 6 years